assertThrows(IllegalArgumentException.class, () -> Stats.meanOf(ImmutableList.<Number>of()));
    assertThat(Stats.meanOf(ONE_VALUE)).isWithin(ALLOWED_ERROR).of(ONE_VALUE);
    assertThat(Stats.meanOf(POSITIVE_INFINITY)).isPositiveInfinity();
    assertThat(Stats.meanOf(NEGATIVE_INFINITY)).isNegativeInfinity();
    assertThat(Stats.meanOf(NaN)).isNaN();

  public static double meanOf(long... values) {
    checkArgument(values.length > 0);
    double mean = values[0];
    for (int index = 1; index < values.length; index++) {
      double value = values[index];
      if (isFinite(value) && isFinite(mean)) {
        // Art of Computer Programming vol. 2, Knuth, 4.2.2, (15)
        mean += (value - mean) / (index + 1);
      } else {
        mean = calculateNewMeanNonFinite(mean, value);
      }

package cmd

import (
	"errors"
)

// errInvalidArgument means that input argument is invalid.
var errInvalidArgument = errors.New("Invalid arguments specified")

// errMethodNotAllowed means that method is not allowed.
var errMethodNotAllowed = errors.New("Method not allowed")

// errSignatureMismatch means signature did not match.
var errSignatureMismatch = errors.New("Signature does not match")

Unfortunately, writing controllers is very error prone, even for seemingly simple cases.
To work around this, Istio has a variety of abstractions meant to make writing controllers easier.

## Clients

Istio offers a variety of increasingly high level abstractions on top of the common Kubernetes [`client-go`](https://github.com/kubernetes/client-go).

```mermaid

  are not Modified Works.

"Contributor" means any person or entity that Distributes the Program.

"Licensed Patents" mean patent claims licensable by a Contributor which
are necessarily infringed by the use or sale of its Contribution alone
or when combined with the Program.

"Program" means the Contributions Distributed in accordance with this
Agreement.

"Recipient" means anyone who receives the Program under this Agreement

      // in NaN naturally.
      sumOfProductsOfDeltas +=
          values.sumOfProductsOfDeltas()
              + (values.xStats().mean() - xStats.mean())
                  * (values.yStats().mean() - yStats.mean())
                  * values.count();
    }
    yStats.addAll(values.yStats());
  }

  /** Returns an immutable snapshot of the current statistics. */

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all

  are not Modified Works.

"Contributor" means any person or entity that Distributes the Program.

"Licensed Patents" mean patent claims licensable by a Contributor which
are necessarily infringed by the use or sale of its Contribution alone
or when combined with the Program.

"Program" means the Contributions Distributed in accordance with this
Agreement.

"Recipient" means anyone who receives the Program under this Agreement